Re: freebsd 13 ryzen micro stutter

On Mon, 22 Mar 2021 23:50:52 -0400
monochrome <monochrome_at_twcny.rr.com> wrote:

> After about 8 months of struggling to narrow this down I did another 
> search and saw this:
> 
> https://www.reddit.com/r/freebsd/comments/lc8fwo/freebsd_13_vega_64_micro_stutter_in_x/
> 
> I haven't seen this come up here so I thought I would bring it up.
> 
> My story started sometime before around August last year when synergy 
> started getting really annoying with stuttering. Pretty sure it
> wasn't like that when I first started tracking 13-current in around
> May 2020 (I was on 12 with scfb for a long time before that with no
> issues), but since then I have tried to eliminate as many variables
> as possible. First I switched to barrier instead of synergy. Shortly
> after that I realized it was happening all the time and not just a
> network problem, I started using foobillard to verify during tests. I
> tried different RAM combinations, different network cards, a variety
> of RAM timings, stripping rc.conf etc, powerd settings, also scfb,
> with no effect. It is observable with ping -f, a dot or two appears
> every time it glitches. It seemed much better with RC2, but now with
> RC3 it seems to be back with a vengeance, and since its my main
> workstation and barrier/synergy server host for several machines, it
> is unbearable to use. Both Win10 and devuan3 on the same machine are
> smooth with no issues. Any feedback or info would be appreciated.
> 
> Hardware:
> ASRock B450M Pro4
> Ryzen 2400G, no OC
> 32M DDR4-2933
> Onboard Vega GPU, drm-fbsd13-kmod
> _______________________________________________

Without knowing much about the issue at hand, just a few ideas:

Sysctls I would look at:
- raising *.cx_lowest
- different kern.eventtimer.timer

Try running with powerd disabled.

Try disabling acpi_thermal (debug.acpi.disabled="thermal") as stated in 
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=234455#c9

Certainly someone else has better ideas though.

Best,
Michael

-- 
Michael Gmelin